8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 OR 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): August 18, 2026

NiSource Inc.

(Exact Name of Registrant as Specified in Charter)

001-16189

35-2108964

(State or other jurisdiction

of incorporation)

(Commission

file number)

(I.R.S. Employer

Identification No.)


801 East 86th Avenue
Merrillville, Indiana		46410
(Address of Principal Executive Offices)		(Zip Code)

Registrant’s telephone number, including area code: (614) 460-6000

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐

Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐

Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐

Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2 (b))

☐

Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4 (c))

Securities registered pursuant to Section 12(b) of the Act:

Title of Each Class

Trading
Symbol(s)

Name of Each Exchange

on Which Registered

Common Stock, par value $0.01 per share

NYSE

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 8.01

Other Events.

6.250% Fixed-to-Fixed Reset Rate Junior Subordinated Notes due 2057

On August 13, 2026, NiSource Inc. (the “Company”) and Barclays Capital Inc., Goldman Sachs & Co. LLC, J.P. Morgan Securities LLC, Morgan Stanley & Co. LLC and Wells Fargo Securities, LLC, as lead underwriters, entered into a Terms Agreement (the “Terms Agreement”) with respect to the offering and sale of $750,000,000 aggregate principal amount of the Company’s 6.250% Fixed-to-Fixed Reset Rate Junior Subordinated Notes due 2057 (the “Notes”) under the Company’s Registration Statement on Form S-3 (File No. 333-291167) (the “Registration Statement”). The sale closed on August 18, 2026.

Interest on the Notes accrues from and including August 18, 2026 and is payable semi-annually in arrears on April 15 and October 15 of each year, beginning on April 15, 2027. The Notes bear interest (i) from and including August 18, 2026 to, but excluding, April 15, 2032 (the “First Reset Date”) at the rate of 6.250% per annum and (ii) from and including the First Reset Date, during each reset period at a rate per annum equal to the Five-year U.S. Treasury Rate (as defined in the prospectus supplement described below) as of the most recent reset interest determination date plus a spread of 1.930%, to be reset on each reset date; provided that the interest rate during any reset period will not reset below 6.250% per annum.

The Notes mature on April 15, 2057. The Company, at its option, may redeem some or all of the Notes during specified periods, and upon the occurrence of certain ratings, tax or tax credit events, all as described in the prospectus supplement.

In accordance with the terms of the Notes, so long as no event of default (as defined in the prospectus supplement) with respect to the Notes has occurred and is continuing, the Company may, at its option, defer interest payments on the Notes, from time to time, for one or more deferral periods of up to 20 consecutive semi-annual interest payment periods each. During any such period during which such payments are deferred, the Company will not (with certain exceptions as described in the prospectus supplement): (1) declare or pay any dividends or distributions on any Capital Stock (as defined in the prospectus supplement), including the common stock, of the Company; (2) redeem, purchase, acquire or make a liquidation payment with respect to any Capital Stock of the Company; (3) pay any principal, interest or premium on, or repay, repurchase or redeem, any indebtedness of the Company that ranks equally with or junior to the Notes in right of payment; or (4) make any payments with respect to any guarantees by the Company of any indebtedness if such guarantees rank equally with or junior to the Notes in right of payment.

The Notes were issued pursuant to a Subordinated Indenture, dated as of May 16, 2024, between the Company and The Bank of New York Mellon (the “Subordinated Indenture”), as supplemented by the Fourth Supplemental Indenture thereto, dated as of August 18, 2026 (the “Fourth Supplemental Indenture”). The Company intends to use the net proceeds from the sale of the Notes for general corporate purposes, including to finance capital expenditures, for working capital and to repay existing indebtedness. Further information concerning the Notes and related matters is set forth in the Company’s prospectus supplement dated August 13, 2026, which was filed with the SEC on August 14, 2026.

The preceding is a summary of the terms of the Notes and is qualified in its entirety by reference to the Fourth Supplemental Indenture attached hereto as Exhibit 4.1 and the form of the Notes attached hereto as Exhibit 4.2, each of which is incorporated herein by reference as though it was fully set forth herein.

The Company is filing Exhibits 5.1 and 8.1 with this Current Report on Form 8-K in connection with the Registration Statement.

Item 9.01

Financial Statements and Exhibits.

(d) Exhibits


Exhibit Number		Description

4.1		Fourth Supplemental Indenture, dated as of August 18, 2026, between NiSource Inc. and The Bank of New York Mellon, as trustee

4.2		Form of 6.250% Fixed-to-Fixed Reset Rate Junior Subordinated Notes due 2057 (included in Exhibit 4.1 hereto)

5.1		Opinion of McGuireWoods LLP regarding validity of the Notes

8.1		Opinion of McGuireWoods LLP regarding certain tax matters related to the Notes

23.1		Consent of McGuireWoods LLP (included in Exhibit 5.1)

23.2		Consent of McGuireWoods LLP (included in Exhibit 8.1)

104		Cover page Interactive Data File (embedded within the Inline XBRL document)

Cautionary Statement Concerning Forward-Looking Statements

This current report on Form 8-K contains forward-looking statements that are not historical facts, including statements about the anticipated use of proceeds from the sale of the Notes. These statements are based on current expectations and assumptions, which management believes are reasonable, and on information currently available to management, but are necessarily subject to various risks and uncertainties. In addition to the risk that these assumptions prove to be inaccurate, factors that could cause actual results to differ materially from those contemplated by the forward-looking statements include factors disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025, and its subsequent filings with the SEC, which are available on the Company’s website at www.nisource.com and on the SEC’s website at www.sec.gov. The Company undertakes no obligation to publicly update or revise any forward-looking statements, whether due to new information, future events or otherwise, except to the extent required by law.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.


		NiSource Inc.
		(Registrant)

Date: August 18, 2026	By:	/s/ Shawn Anderson
		Shawn Anderson
		Executive Vice President and Chief Financial Officer